Lifting device.



R. D. GARDNER. LIPTING DEVICE.

APPLICATION FILED APR. 28, 1913. 1,09 1,829. Patented Mar. 3 1, 1914,

' 2 QHEETs-SHEET 1.

R. D. GARDNER.

LIFTING DEVICE. APPLICATION FILED APR. 2a, 1913.

Patented Mar. 31, 1914.

2 SHEETS-SHEET 2.

| I l I I I I I I l L I l I I l l l ll LVVE/VTOR. Mu bw IVJTNESSES:

ATTORNEY.

in ra mar anion.

RANDALL I). GARDNER, OF BOSTON, MASSACHUSETTS.

LIFlINGr DEVICE.

Specification of Letters IPatent.

Patented Mar. 31, 1914.

1/ b all whom it may concern Be it known that. I, RANDALL D. GARDNER, ofBoston, in the county of Suffolk and State of Massachusetts, haveinvented a new and useful Lifting Device, of which the following is aspecification.

The chief objects of my invention are to provide simple but quick,accurate and citicient mechanism for lifting heavy loads andparticularly the ends of draw-bridges and my invention consists partlyin a device for raising the member to be lifted so that a bearing blockmay be inserted, partly in means for centering the device, partly inmeans for preventing movement after the device is in place and partly ina mechanical automatic control for an electric motor which operates themechanism although this automatic device is useful for other purposes.

In the drawings: Figure 1 is an elevation of a device embodying myinvention; Fig. 2 is a plan of the same; Fig. 3 is a detail showing thecentering mechanism; Fig. l is a detail of a modification; Fig. 5 is anelevation of the automatic mechanism for operating the reversing switch;and Fig. 6 is an end view of the same.

The lifting device may be attached to the member to be lifted in anysuitable way and in the case of a drawbridge it may be attached to thegirders, floor-beams or as shown in the drawing to a frame A suspendedunder the ends of the draw. Links a a form with the gear segments oractuators Z) Z) toggle joints for forcing the lower end of the liftinglinks 0 0 forward, link a being pivotally connected to segment Z2 at jand also pivotally connected to links 0, the latter being pivoted attheir upper ends to swing on pin (Z. At the lower end of links 0 arepins 6 upon which one or more rolls 00 m are mounted, these rolls takingthe weight of the load at the time of lifting. Sliding block 7 isslightly beveled on its lower face and is mounted to slide in guides g9' attached to the bottom of frame A and has a pin and slot connectionwith links it la, the other end of links it it being pivotally connectedat if to the segments Z) Z).

B is a bearing block fixed to the draw landing in the form shown uponwhich block the rolls a" 02 move when lifting or lowering the load andupon this bearing block the sliding block 7 rests when it is supportingthe ends of the draw or other member. In Fig. 3 I show the beveled edges6 b and these are engaged by the rolls :0 as they are forced forward andthe result is that the end of the draw-bridge is brought to an accuratecentral position and the rolls remaining one on each side of the raisedportion 6 of the bearing block B lock the draw against turning untilthey are withdrawn as hereinafter described. At either side of theraised portion 6 are the curved tracks 19 upon which the rolls w w rideto lift the end of the drawbridge for insertion of the sliding block andas the rolls then move along the horizontal portion o it will be clearthat the end is lowered so that the sliding block rests upon the bearingblock giving a rigid support to the drawbridge.

When the end of the drawbridge is to be released the gear segments aremoved upward on the shaft in, this movement causing the rolls w x toswing to the right on an arc with reference to the pin (Z, whichmovement along the horizontal portion 6 elevates the end of thedrawbridge and thus releases the sliding block 7 which, on account ofits sliding connection with link it, does not move until the end hasbeen lifted to a sufficient extent but further movement of the segment 6draws the sliding block along its guides until it reaches the dottedposition shown in Fig. 1. In the meantime the movement of the rolls downthe inclines 79 allows the end of the drawbridge to drop to its loweredposition. When the gear segments 1) are in their highest position theblock f and rolls 00 are fully withdrawn as shown in dotted lines at as"and f allowing the ends of the drawbridge to swing clear of the bearingblock B. In the reverse operation for lifting the drawbridge the gearsegment starts downward and thrusts the rolls m to the left (as shown)and these rolls ride up the inclines 5 and raise the drawbridge awayfrom the bearing block, the sliding block 7 being in the meantime, owingto the pin and slot connection, at rest but when the slot has completedits travel over the pin then the sliding block is moved along its guidesinto position over the bearing block. Ihe first effect of movement ofthe rolls is to center the drawbridge and later the rolls raise the endand allow the sliding block to be moved into operative position,

the sliding block having the faster movement owing to the position ofthe pin it on the segment and then as the rolls move along thehorizontal portion 6 the end of the drawbridge is lowered and the weightis transferred to the sliding block 1, the rolls locking the end of thedrawbridge against movement until they are subsequently withdrawn.

r The bearing block may be of the shape shown in Fig. 1 or of any othersuitable shape an example of which I have shown in Fig. i, the partsbeing lettered as in Fig. 1, but the bearing block being guided inguides g which are at an angle with frame A and said block being in aslightly different location with reference to link 0 the latter, in theposition shown, holding member A in its highest position and movement ofthe rolls in either direction lowering member A. The automatic'mechanical device for controlling the motor D which operates thelifting mechanism is shown on a larger scale in Figs. 5 and 6 in which Nis a suit-able frame or support in which turns shaft n which is adaptedto-engage nut 79 the latter engaging an adjusting screw 1' when movingin one direction and another adjusting screw 1" when moving in theopposite direction. As the nut 79 is prevented from rotating by theguide '3 it moves longitudinally and therefore moves the adjusting screwand as the latter is mounted on rack q said rack will be moved and saidrack engages teeth on gear segment .9. As segment s moves on shaft mtothe position shown in Fig. 5 it raises the weight t and as the'center ofgravity of the latter passes the vertical it tends to drop to the rightin Fig. 5. This tendency is for a time retarded by a spring pin engagingguide 20 in member 25 but when the latter has fallen sufficiently itreleases itself from the spring pin and falls with a sharp quick blowonto gear segment a, turning on shaft m, and segment a then turns shaft'0 through 90 to reverse the switch indicated at E.

\Vhen the motor I) is started the turning of the screw shaft n which ispart of, or geared to, the motor causes the nut 79 to movelongitudinally and thereby, through the rack '9' and segn'ient 8 liftthe weight until thelatter passes the vertical and then it falls, givinga blow which quickly shuts ofi the current, leaving the motor inposition to start in the opposite direction in which case shaft itrotates in the opposite direction carrying nut 72 in the oppositedirection and turning segment 8 in the opposite direction, raising theweight from its position at t until it passes the vertical when it dropswith a quick blow on the other end of segment at which then rotates andreverses the switch. It will be clear that my automatic mechanicalcontrol may be accomplished by means of various actuating mechanisms andany suitable connections may be made between shaft n and shaft 76. Ifdesired shaft is may be turned by hand or a suitable hand operatedrotating device although I prefer the use of a motor so that theoperation may be controlled from some remote place.

A reat advantage of my automatic mechanical device is that it does notget out of order when exposed to moisture as might be the case withelectrical control and this consideration is particularly important inthe case of drawbridges.

What I claim is:

1. A lifting device comprising a fixed bearing; a rotary member to belifted; a sliding block; means to move the member to be lifted away fromsaid bearing, said means including a member cooperating with the fixedbearing to adjust centrally the member to be lifted; means to insert thesliding block between said bearing and said member when the latter islifted, said moving means being movable while the block is stationary;and an actuator to actuate both of said means.

A lifting device comprising a fixed bearing; a rotary member to belifted; a

sliding block; means to move the member to be llfted away from saldbearing, said means including a. member cooperating with the fixedbearing to lock said member against rotation; means to insert the sliding block between said bearing and said member when the latter islifted, said moving means being movable while the block is stationary;and an actuator to actuate both of said means.

3. A. lifting device comprising a member to be lifted, a fixed bearinghaving beveled faces and a track; rolls pivot-ally connected to themember to be lifted, the pivot being at a greater distance from oneportion of the track than from another port-ion and the bearings for therolls being connected together rigidly, said rolls engaging said beveledfaces to center said member and riding upon said track to move saidmember away from, and allOw it to move toward, said bearing; a beveledsliding block; a reciprocating rotary member; means to move the latter;a link connection between the rolls and the rotary member; and a linkcon nected to therotary member and having a pin and slot connection withthe sliding block, all combined to move the member to be lifted awayfrom the fixed bearing for insertion of the sliding block and forlowerthe sliding block between said bearing and said member when thelatter is lifted, said moving means being movable while the block isstationary and an actuator to actuate both of said means.

5. A lifting device comprising a fixed bearing; a member to be lifted, asliding block, means to move the member to be lifted away from saidbearing; means to insert the sliding block between said bearing and saidmember when the latter is lifted, said moving means lowering said memberon to said block after said insertion and said moving means beingmovable while the block is stationary and an actuator to actuate both ofsaid means.

(3. A lifting device comprising a fixed bearing; a member to be lifted,a sliding block, means to move the member to be lifted away from saidbearing; means to insert the sliding block between said bearing and saidmember when the latter is lifted, said moving means lowering said memberon to said block after said insertion, said block being immovable whenthe load of said member rests upon it and an actuator to actuate both ofsaid means.

7 A lifting device comprising a fixed bearing; a member to be lifted, asliding block, means including a toggle joint to move the member to belifted away from said bearing; means to insert the sliding block betweensaid bearing and said member when the latter is lifted, said movingmeans lowering said member on to said block after said insertion; and anactuator to actuate both of said means.

8. A lifting device comprising a fixed bearing; a member to be lifted; asliding block; means to move the member to be lifted away from saidbearing; means to insert the sliding block between said bearing and saidmember when the latter is lifted, said inserting means including a linkhaving a pin and slot connection With said block, said moving meanslowering said member on to said block after said insertion; and anactuator to actuate both of said means and having during all itsoperation simultaneous movement wit-h said moving means and havingdirect connection with said link.

9. A lifting device comprising a fixed bearing; a member to be lifted; asliding block; means to lift said member away from said bearing and tolower it onto said block; an actuator to actuate said means and toinsert said block between said member and said bearing; means connectingthe ac tuator and lifting means to provide movement of the lifting meansduring all the operation of the actuator; and means connect ing theactuator and block and having provision for relative movement betweenthem during a portion of their operation, all combined to raise saidmember for the insertion of said block and to lower said member ontosaid block after the latter has been inserted and to raise said memberwhile the block is stationary.

10. A lifting device comprising a member to be lifted; a fixed bearing;a movable block to rest on said bearing and to support said member;means engaging said bearing to lift said member away from said bearingand to lower it onto said block; and an actuator for operating saidlifting means and. also for inserting said block between said bearingand said member and for withdrawing it; and a connection between theactuator and block to allow the block to remain stationary during aportion of the movement of the actuator.

11. A lifting device comprising a member to be lifted; a fixed bearing;a sliding block; a link pivotally connected to said member and adaptedto ride on the fixed bearing; a pivoted actuator; a second linkconnecting the first link with the actuator at a distance from the pivotof the latter, the actuator and the second link forming a toggle jointto operate the first link to raise said member away from said bearing;and a connection between the actuator and the block to insert the latterbetween said member and the fixed bearing.

12. A lifting device comprising a rotary member to be lifted; a fixedbearing having a raised portion; a sliding block; a lifting memberconnected with the rotary member and engaging the fixed bearing to liftthe rotary member away from the fixed bearing, said lifting memberhaving projections adapted to engage said raised portion at each sidethereof to prevent rotation of the rotary member; an actuator to operatesaid lifting member and also to insert the sliding block between saidbearing and said rotary member and in position on said bearing, saidactuator having connections with said block and said lifting member tocause the latter to raise the rotary member from the sliding block whenthe latter is sta tionary and in position between the rotary member andthe fixed bearing.

13. A lifting device comprising a member to be lifted; a link pivotallyconnected to said member and having a roll at its free end; a fixedbearing having a track for said roll, one portion of the track being ata greater distance from said pivot than another portion; a rotaryactuator; a second link pivotally connected with the first link and alsopivotally connected with said actuator; a sliding block; a link having apin and slot connection with said sliding block and having pivotedconnection with said actuator, all combined to insert said block inposition on said bearing after said member has been. lifted, to lowersaid member onto said block, to lift said member from said block Whilethe latter is stationary and to ing block between said bearing and saidWithdraw said block from its position on member When the latter islifted; and an acsaid fixed bearing. tuator to actuate both ofsaidmeans.

14:. A lifting device comprising a member RANDALL D. GARDNER. to belifted; a fixed bearing; a sliding block; 1 lVitnesses: means to movethe member to be lifted away ARTHUR l3. RANDALL, from said bearing;means to insert the slid- GEORGE A. ROOKWELL.

Copies of this patent may be obtained for five cents each, byaddressing'the Commissioxier of Batencs,

Washington. D. C.

